Preclinical Evaluation of a Novel TSPO PET Ligand 2-(7-Butyl-2-(4-(2-[ 18 F]Fluoroethoxy)phenyl)-5-Methylpyrazolo[1,5-a]Pyrimidin-3-yl)-N,N-Diethylacetamide ( 18 F-VUIIS1018A) to Image Glioma

Dewei Tang, Jun Li, Michael L. Nickels, Gang Huang, Allison S. Cohen, H. Charles Manning

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Purpose: There is an urgent need for the development of novel positron emission tomography (PET) tracers for glioma imaging. In this study, we developed a novel PET probe ([ 18 F]VUIIS1018A) by targeting translocator protein (TSPO), an imaging biomarker for glioma. The purpose of this preclinical study was to evaluate this novel TSPO probe for glioma imaging. Procedures: In this study, we synthesized [ 19 F]VUIIS1018A and the precursor for radiosynthesis of [ 18 F]VUIIS1018A. TSPO binding affinity was confirmed using a radioligand competitive binding assay in C6 glioma cell lysate. Further, dynamic imaging studies were performed in rats using a microPET system. These studies include displacement and blocking studies for ligand reversibility and specificity evaluation, and compartment modeling of PET data for pharmacokinetic parameter measurement using metabolite-corrected arterial input functions and PMOD. Results: Compared to previously reported TSPO tracers including [ 18 F]VUIIS1008 and [ 18 F]DPA-714, the novel tracer [ 18 F]VUIIS1018A demonstrated higher binding affinity and BP ND . Pretreatment with the cold analog [ 19 F]VUIIS1018A could partially block tumor accumulation of this novel tracer. Further, compartment modeling of this novel tracer also exhibited a greater tumor-to-background ratio, a higher tumor binding potential and a lower brain binding potential when compared with other TSPO probes, such as [ 18 F]DPA-714 and [ 18 F]VUIIS1008. Conclusions: These studies illustrate that [ 18 F]VUIIS1018A can serve as a promising TSPO PET tracer for glioma imaging and potentially imaging of other solid tumors.

Original languageEnglish
Pages (from-to)113-121
Number of pages9
JournalMolecular Imaging and Biology
Issue number1
StatePublished - Feb 15 2019


  • Cancer imaging
  • DPA-714
  • Glioma
  • Molecular imaging
  • PET
  • TSPO
  • VUIIS1018A


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